It is fitting that Marshes: The Disappearing Edens, at the Carnegie Museum of Natural History, is displayed near the corridor to the Carnegie Museum of Art. The photographs in the exhibit, captured by photographer and writer William Burt between 1975 and 2001, manifest a finely tuned balance between scientific record and aesthetic contemplation.

The show's 40 archivally pigmented inkjet prints, captured using a large-format camera, are the result of Burt's longstanding obsession with the extraordinarily rare and reclusive waterfowl that live in North American marshlands. From rails and bitterns to grebes and gallinules, Burt untiringly stalked his subjects, many of them nocturnal, until he could capture their images through keyhole openings in the tall grass.

Still, marshland birds comprise only a small portion of the exhibition. Burt has also recorded the majesty of weather patterns, the seeming infinity of yawning marshland vistas, and the opulent sapphire of sky reflected in briny water. His images of cascading flowers and soft pliant grasses lying in wind-blown tousles all communicate a silent awe -- a sense of wonder before the marshlands, and the invisible rhythms and patterns that shape the natural world.

This collection is but a sampling of the 90 images that will appear in Burt's new book Marshes: The Disappearing Edens (Yale University Press). Some of the exhibition's photographs have also appeared in Burt's compilations Rare and Elusive Birds of North America (2001) and Shadowbirds (1994), making Disappearing Edens something of a career retrospective.

Conceived by Burt as a ready-made traveling exhibition, Disappearing Edens was chosen for the Carnegie by Sandra Budd, the museum's traveling-exhibits chair. Images are grouped thematically, with an eye for aesthetic impact. The downward spill of tiny pink flowers in "Sea Pinks & Spartina, Elliot Island, Maryland" is balanced by the upward spray of reddish-gold leaves in "Red Maple, Marsh Edge, Old Lyme, CT." As in his books, Burt's writings are sprinkled throughout the exhibition, along with quotes from such authors as Thoreau and naturalist Edward Howe Forbush.

There are obvious corollaries between Burt's work and that of John James Audubon, famous for his naturalistic representations of American birds. Audubon likewise ventured into the wild. And Burt's photographs display the scientific concentration and jewel-toned intensity of Audubon's sumptuous oil portraits of birds -- which Audubon published in Liverpool in 1827 as a book of hand-colored etchings and aquatints under the title Birds of America.

But the parallels end there. Audubon, whose name is now synonymous with ecological and avian preservation, hunted his subjects using fine shot, and then stuffed and mounted them, showing little regard for their potential extinction. And the rarer the specimen, the more avidly Audubon sought it. Burt (who himself has produced photos for the Audubon Society) has tracked his subjects with equal zeal, but with the concern of an environmentalist. He observes their habits and takes their photos, but leaves them unharmed. Through his work, he brings their habitat, now jeopardized by human encroachment, to the attention of an audience perhaps unaware of a wetland's secret microcosm -- or even what a wetland really is.

Also unlike Audubon, whose work is a kind of visual taxonomy, Burt has laced a narrative thread through his exhibition. The plot is chronological and geographical, telling the story of organic similarity, geographical distinction, and the ever-shrinking boundaries of an ostensibly infinite and uncharted wilderness. By drawing together disparate geographical locations and chronological points, he not only tells a personal story of his ongoing preoccupation with marshland topography, but captures the individual characteristics of marshes in Connecticut, Maryland, New Hampshire, Virginia, Utah, Manitoba and Saskatchewan, with all their inherent drama.

While the title Disappearing Edens indicates the critical immediacy of confronting marshland destruction, Burt's photographs appear timeless, a visual record of a landscape seemingly unchanged since antediluvian times.